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Wilshire Grand Tops Out

The tallest tower in the West has topped out. The final 35-foot steel beam was put into place Tuesday, March 8 for the 1,100-foot Wilshire Grand Center in Los Angeles, California. Members of the project team, including Thornton Tomasetti engineers, were on hand for the completion of the building’s central concrete core. Work on the tower began in February 2014 with the largest continuous placement of structural concrete according to Guinness World Records, with more than 21,000 cubic yards of foundation mat concrete placed in less than 19 hours. Thornton Tomasetti provided structural engineering and performance-based design services to engineer-of-record Brandow & Johnston, and model interoperability programming for architect AC Martin. The 73-story tower’s lateral system consists of a nearly rectangular four-cell cast-in-place reinforced concrete shear wall core supplemented by transverse outriggers with buckling restrained brace (BRB) diagonals for well-controlled wind and seismic performance. The gravity system consists of concrete-filled metal deck floor slabs supported by composite wideflange steel framing on concrete-filled steel box columns. Thornton Tomasetti applied performance-based design principles and nonlinear response history analyses to validate the tower’s seismic performance. Leading the project team are Len Joseph, Kerem Gulec and Chuan Do. The building, which will be the tallest in the U.S. west of the Mississippi, is scheduled for completion in March 2017.